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ATF Bunch Compressor

Bunch Compression Overview

An advanced magnetic chicane bunch compressor has been installed at the ATF that will produce short and/or energy chirped bunches. The compressor itself is an experimental object, where the effects of coherent synchrotron radiation and non-inertial space-charge forces. In the context of this project, the compressed beam will be used in ATF beamline 3, to inject an ultra-short, high brightness electron beam into the VISA undulator, driving a SASE FEL into saturation in less than 3 m.

Future studies characterizing the CSR/CER emitted between the third and fourth magnets are on going.


Rendering of the full ATF compressor system

ELEGANT simulations




Phase spaces, emittances and twiss parameters of interest
various plots

Longitudinal Phase Space

Current Profiles

Bunch Length Evolution / Spot Size
***With the CSR turned on***
property Initial Beam Final Beam
     
current 40-45 amps 1.5Kamps
emit, x 1.45 mm-mrad 1.49 mm-mrad
emit, y 1.47 mm-mrad 5.755 mm-mrad
X, rms .39 mm .14mm
Y, rms .39 mm .14mm
length, rms 400 microns 24 microns
beta x 15 m 1.9 m
beta y 15 m 1.9 m
alpha x -1 7.00E-12
alpha y -1 -0.77
***With the CSR turned off***
property Initial Beam Final Beam
     
current 40-45 amps 1.5Kamps
emit, x 1.45 mm-mrad 1.49mm-mrad
emit, y 1.47 mm-mrad 3.12mm-mrad
X, rms .39 mm .14mm
Y, rms .39 mm .188mm
length, rms 400 microns 257 microns
beta x 15 m 1.9 m
beta y 15 m 1.9 m
alpha x -1 7.00E-12
alpha y -1 -0.77
The above parameters and the attached plots are all either taken from the beginning
of the H-line or at the entrance to the dogleg. The one exception is the spotsize
plot which is shown at the symmetry point of the compressor.